The invention relates to a cooling apparatus used in case of measurement in a low temperature range in a thermal analysis apparatus or a viscosity and elasticity measuring apparatus.
Systems of this kind which have been used up to now include a system making a temperature control by means of only a heating furnace while keeping a quantity of vaporized liquid nitrogen constant and a system making an on-off control of a heater in liquid nitrogen.
The above-mentioned prior arts have disadvantages such that a great amount of liquid nitrogen is consumed due to the necessity of keeping always an amount of vaporized liquid capable to attain the lowest temperature and pulsating current of nitrogen gas is caused by an on-off control action of the heater.